shipley



if? COMM/@SES PPLICATIN HLED MAY 2, lgf

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Patented Exec. MS, l.

-SHEET L ATTORN UNITED AsTaTEs PATENT oEEroE.

THOMAS SHIPLEY, 0F YORK, PENNSYLVANIA.

REFRIGERATING OR ICE-MAKING- APPARATUS. f

To all 'who/'1L it may concern: j

lie 1t known that I, THOMAS SHIrLuY, a-

.ciitizen of the United States, residing at York, in the county of York and State of Pennsylvania, have invented-certain new and useful Improvements in lefrigerating or Ice-Making A iparatus, of which the following is a speci cation.

My invention relates to a refrigerating orice making system or apparatus of the compression type, in which the ammonia,` or other refrigerant fluid, circulates in a closed circuit including a compressor, a condenser, a receiver, and an evaporator wherein the effective or useful work is done, the refrigerant passing'from the discharge slde of the compressor successively to and through the condenser, the receiver, tlie evaporator, and thence back to the compressor on the suction side of the same. -Plants of this character are usually designed with reference to a. certa-in normal rateof production, say 1.00 tons refrigeration or ice making, or what not, per diem, and the different members Aot thel plant are designed with a. view to effecting that result Iwith the greatest practicable etiiciency and economy.

Not infrequently however `it becomes desirable to rim plants of this type at times or for a season at "less than normal or full capacity. In such cases a considerable increase of horse power per ton of refrigeration or ice making takes place if. the speed of the compressor remains the same. In these circumstances the volume of gas handled remains the same while the work being done is lessened, and this results Vin lowering the pressure, of the gas-the blick pressure or suction pressure so-called-a nd correspomling temperature on the evaporating side of the system, and consequently in requiringr a corresponding ,Lcrease of horse power per ton of work done to compress the gas in the process of liquefying it.

lt has long been known that, on such occa` sions, the normal suction pressure could be maii'itained, 'and even increased, by reducing the speed of the compressor; 'and in cases 'where the means for operating the compressor were snc-h (steam engines for exy ample) that its speed could be economically reduced in proportion to the reduction in the work to be done, the advantage of op`- erating at the' highest possible suctionvpressure could be utilized. l

But other 1i'icans,-gas and oil engines and Specification of Letters ratent.

electric motors-for operating the compressor, which have comparatively recently come into extensive use. as a power for such purpose, were not such that the speed of the compressor could be econolnically reduced proportionately to the reduction in the work to be done, and the many efforts which have been made to provide them `with means for speed regulation to meet the iuctuations of powerv required, have met with only partial success, at the best. In the case of variable speed electric motors, speed regulation of the compressor can be accomplished, but not with an accompanying lreduction in the use of current; in the case of gas andoil engines, it can be accomplished to a very limited and unsatisfactory extent only'.

In addition to the loss in economy 'ex'- perienced on such occasions, there arel other serious disadvantages encountered when the relation. between the work to be done and the speed at which the compressor must run is such that the resultingsuction pressure and its corresponding temperature are very low; not infrequently this temperature becomes so low'that the coolingfwater in the jackets of the compressor cylinders freezes andbursts the cyllnders and their jackets, and, when the compressor happens to be of the now popular nclosed type containing in its inclosing case o'r housingthe oil for the lubrication of its working parts by -What is known as the splash system, the oil congeals and does not lnbricate the said parts effectively, which results in their heating and scoring and sometimes breaking.

The object of my invention is to 'provide means' whereby all devices for speed regulation of the compressor-at present known or used-may be profitably dispensed with, and the suction pressure may be varied at will to conform to fiuctuations in the work to be done, 'While the speed of the compressor remains constant, thus Ypermitting lthe plant V-to operate at all times to the best advanta To this end my invention may be stated to consist in a closed refrigeration or ice making system of the compressor type here- -inbefore specified in which the compressor is associated with an auxiliary clearance chamber communicating with the interior of the compressor cylinder on the compression side of the piston therein, and provided with means by which the volumetric capacity of, or in other .words the clearance in, said Patented Dec. 16, 1919.

Application med May 24, 1919. serial No. 299,420.

Chamber, and consequently the clearance in the compressor as a Whole, may be increased or decreased, whereby, without changing the "speed of the compressor, its capacity can be .so regulated as to Vary at will the pressure "on the suctiop-side of the piston to conform t0 the fluctuations in the Work to be done.

Under normal conditions con'imunication between the clearance chamber 'and comrexpands on each suction stroke of the pistonv and thereby correspondingly reduces i' the Volume of the incoming gas from the suction side on such stroke, and this in turn correspondingly' raises the pressure on the suction or 'evaporating' side of the system.

i .By providing means whereby, While the compressor is in. operation, the vvolumetric capacity of the clearance chamber vcan be varied at will toregulate the amount of gasadmitted to it from the cylinder, the plant can at all times be run under the backprcssure best suited for the ivork to b e done. j Obviously y the ell'ect of the use of.. the

clearance chamber will be areduced per' centage 'bf the volumetric' capacity .of the compressor, but the loss will be so much more than compensated by the higher back pressure obtained that the net result will be a -less'horse power per ton for the lesser workon such occasions than for the greater work when running at full capacity.

To enable others to bcttenunderstandand use my invention I will now proceed to vde,- scribe more in detail Athe manner-in which it is or may be carried into effect by reference to the ac co'mlianying drawings, forming part of this specification, in which- Figure l is a representation largely diagraniniatic of an apparatus embodying my invention in its preferred t'oriii.

Fig. 2 is an axial section on an enlarged scale of so nuich of a single acting -vertical compressor machine with iny improvement applied thereto, as needed .for the purpose of explanation.

Fig 3 is an axial section von still larger scaleo'f a portion of tho clearance chamber and the devices n controlling communication betivecn it and thc compression cylin-f der, aslwell as for varying its volumetric capacity. Y

Confining attention to Fig. 1, C is the condenser in which the compressed ammonia gas, led through .pipe 4 from the high pressure or discharge side of the' constant speed single actingr compressor D (of any usual.'

or suitable type), is liquefied; A is the, recciverinto which the liquefied ammonia is discharged from the condenser through pipe l; la is the evaporator in'which the useful work is done, and which draws its,l supply of liquid ammonia for this purpose fronrthe receiver A through pipe 2 and 7o returns it in the form' of gas to the low pre:- sure or .suction side of thecompressor l; through pipe 3, to he again compressed and returned to the condenser, thus completing the cycle. The auxiliary clearance chamber hereinbeore.referred to is shown as'a cylinder F mounted on the discharge end ot the compressor lcylinder and communicating with the interior of the sameon the compression side of the piston therein. The means 8o -for regulating the `volumetric capacity of the auxiliary clearance chamber aretypitied by a piston (hand a screw threaded piston rod H extending through and engaging a screw or normal, capacity,.coimnunication betweenthe clearance chamber and compression cylinder .is closed as represented 'in/'the figure wherein the .piston yGv `is-shown in position to cut ott the clearance chamber entirely from 55 the' compressor cylinder. ,If however the amount. ofnwork to be done-is for any .reason .i-educedfbelow. the full per diem-capacity for .wl'iich tliefplanti'sdesiged, the piston*- G, bymeansof' itsscrew steinH and handle 100 1 is moved to-,openviride the auxiliary clear.-

lance'g'zh'am'ber vtothe admission of gas from the compressor cylinder,` and 'is so adjusted as to regulate the space available forthat purpose .'within the auxiliary clearance`l05 chamber, or in other vyordfthe 4clearance in said chamber, and consequently the clearance .in the compressor asta Whle, as required to produce and 'maintain vthe back, or suction,

pressure best 4suited `for the work` to be done. 110

The thus 'admitted to the adjustable clearance chamber 'from the compressor cylind-er rexpan'ds oneach suction stroke orf the compressor piston, "and thereby limits the amounto'f incoming. gas o'nl such sti-olie; iis and this in turn raises Athe suction or back pressure with the resulting net-economical gain. in less-horse power per ton for the lesser workthan is'required for the greater not-fk when ,running at full c( pacity as hcreinrbefore explaine A vave controlled pipe connection .5 lbetween the high 'pressure side of the system and =the head' of the" clearance chamber above the piston lthereincan beprovidedv to balance the pressure on 1-25 the clearance Ichamber piston G when an ad] ustment of the clearance 1n said chamber is neede.

The s 'uctural details of the clearance device,`.jand the manner of applying it' to the 130 compressor cylinder can, without departure -from my invention, be widely varied, de-

the discharge valve inthe safety' head ot' the cylinder; SV the suction valve in piston J. These parts may be of any usual or sultable construction; and their mode ot' operation and the manner in which they are as a whole connected up' in the closed ammonia circulating systemof Fig. v1 will be understood without further explanation.

F 'is' the cylindrical auxiliary clearance -chamber suitably secured fto, and projecting laterally. in .horizontal position from, the side of the vertical compressor cylinder, and communicating with the interior of the said compressor cylinder through a tubular stem 8, secured at its outer end `in a tubular past sage .9 formed in the hase of the clearance chamber and extending therethrough to the interior of the latter, and at its inner end en- `tering and fitting an opening formed'inthe side of the compressor cylinder a little lne-- low the safety-head'T, the said tubular stem the piston.

serving to .put the clearance 'chamber in commun'ication with the interior of the comT presser cylinder on,the compri asien side of The clearance regulating piston G fits the interior of theclearance chamber closely and it is provided with suitable, packing tomakea tight joint between the` two. The front portion of thepiston, in this instance, is preferably of truste-conical shape as shown and in closed position fits closely against the adjoining head of the clearance chamber which is correspondingly recessed to receive it. L is the tubular piston adjusting rod which extends out through .ajstuing box M on the outer head of `thea clearance chamber, and thence .extends through a rotary internally screw threaded regulating nut N which is mounted to rotate' vwithout longitudinal movement-ina suitable hearing on the outer endo'fthe stand O cast in one withdor otherwise suitably secured tothe outer head of the clearance chamber. Thel rod L is externallyT screw threaded to engage the nut N andv is provided with an operating wheel lV Aon its outer end, by which the piston can be adjusted to regulate the clearance in the auxiliary chamber as desired, or-indeed to exclude the gas entirely from the chan'ihci'. I prefer however to employ for the last named purpose a separate and independently movable and operable stop plug R for closing the clearance port in the side et the compressor cylinder t irough which the tubular stem S' communicates with the-interior of said cylinder. The stem 8, the clearance piston rod L for a portion of its length md the opening in the clearance piston between the two are all .of the same internal diameter and lin axial alinement'with one another, and the, stop plugR is ot' such diameter as to fit closely but slidably therein. 'l`he;stop plug, has a spline and groove connection 10 with the tubular regulating rod L topermit iti-to move lengthwise therein without rotation. For the purpose of operating the .stop plug 'l provide a stem S, the screw threaded trent portion of which enters the .plug and env gages a correspondingly internalv screw.

thread formedin the rear end ot the tubular. .portion of the stop plug' whlch 1s shghtly internally contracted for that, purpose shown. The stem S extends rearwardly and' axially through the tubular clearance piston rod L, the internal diameter of the rear por tion ot the said rod being reduced so that it shall fit closely,4 and furnish a bearing for` `the plug operating stem. Said stein passes ont through a stntling hoxfM on the rear end et the tubular clearance-piston rod and is provided with suitable means for permit'- ting' it te rotate without longitudinal movement-in this instance an annular collar on it which-is confincdin the stuffing box M as shown. vided with an operating handle X by which the stop' plug can be operated to open 'and close the po'rt which it controls as desired.

ll'hile, with careful workmanship, the clearance piston can` he made to tit so closely against the innercylind'ricaljsurface of the clearance chamber as to prevent4 any gas from passing through to the space in rear of the piston, thus permitting' a valve con- 0n its-rear endftbe stein is' pro' trollcd communication 5 directly between valve-controlled oilv supplycconnhction .V2V

between the. reservoir andatheol-iter endlof the. clearance chamber; a hand-valve-controlled connection V3,f5, 4between the' top ot the oil reservoir and the high pressure side of the circulating system; and a hand valvecontrolled connection V4. 10, between the top of the oil reservoir and the low pressure 'side of the system, connection 10 leading to the low pressure side. precisely m the same way in which connection 5 leads to tpe high pressure side. The reservoir is a so provide( with a sight gage 1l for indicating the level eivoir fills the connection between the resersure valve V3 voir and the clearance chamber as well as that portion of the interior of said chamber back of the clearance piston The filling connection V i's opened only when more oil is to be .supplied to the reservoir; at other 'times it is closed.

When the plant is in operation with the clearance piston adjusted to give the auxiliary clearance required, the connection VL between the oil reservoir and the clearance chamber high pressure and low pressure connections have noeffect upon` the operation of the clearance device-proper. valve V4 also is closed; but the high presis open, :thus subjecting the oil in the reservoir to pressure from the high pressure side of the system.

V\7l1en l1owe\ "er, while the system is in operation, it is desired for' any reason to make a dii'erent'adjustment of the clearance piston for the purpose ofl increasing or decreasing the clearance in the auxiliary clearance chamber, the4 valve' V2 between the reservoir and the clearance chamber isA opened with the effect of balancing.,r the pressure`on the clearance piston and permitting its ready and safeadjustnieiit, b 7 means of its adjusting:r rod L and "operating hand Wheel WV. After the auxiliary clearance has thus been adjusted, the valve V2 between the clearance chamber and oil reservoir is again closed and the operation' goes on as before. Thus the only balancing done bythe oil isduring theperiods when an adjustment of the clearance is beingr made in theclearance chamber.

The low pressure connection V4, 10- which is a nicety rather than a. necessity-is provided as a convenient means for pumpinef out the gas from the reservoir whenever desired-as for example when it becomes necessary to replenish the charge of oil. In such case the' high 'pressure valve V3 should be closed and the low pressure valve V4 opened, thus permitting the gas to' be pumped out of the reservoir through itsconnection 10 with the low pressure or -The reservoir can -then be refilled with oil through the valve-controllcd fillingv connection, after which the low prcssurevalve V4 'caube closed and the high pressure valve reopened.

Malnifestly the Iforni and structural dctails of thc cmlmdimcnt of my invention can be widely varied without departure .from the spirit of my invention; I do not limit my claims therefore to thc structural details hereiuheforc shown and set forth in is closed and the reservoir and its The low pressureY ste-in and handleas described.

the combination specified in vclaim 3,'a

' the oil therein,

me of carrying the same into system of the compression type.,`- the combi-- nation with the compressor and its connections with the highv prssure and low pres-` sure sides'of said .system respectively, of an auxiliary-clearance chamber communieating with the interior of the compressor cylinder on the compressionside of the piston `therein,' ance in said'auxiliary cle( and consequentlythe cleara ce in the coinpressor as a whole, may be increased orvdecreased, whereby the capacity of the cgm-` presser can, without eliaiicnfze'l its speed, be

and means by Phich the clear` visy rance chamber,

varied to conform to the iuiuationsin the l j work to be done. In combination with the yelements of 2. the combination specified -in the preceding claim, manually opera-ted means-independent of the means for regulating the volumetric capacity of the .auxiliary clearance chamber, for opening and closiiigoommu- `n ication .between said chamber and 4the interior of the' compressor cylinder.

1,3. TheL con'ibination of-tlie elements'specified in claim-1, whentlie means for varying the clearance in fthev auxiliary clearance chamber comprise a. piston 'and operatllig,A

4. In combination with the elements o i controlled 'connection between the circulating system' on the discharge or high pressure side of the mmpressor and thel auxiliary clearance chamber on the side of the pistonthereinopposite lthat on which the said chamber communicates with the coinJ presser cylinder.- 'l

In combination withthe elements of the combination spccifiedgin claim 3, an oil reservoir, la valve-'controlled connection between the Same and the 'head of the clear-Y ance chamber on the side of the 'piston therein opposite .that von which the clearance chamber communicates with cylinder, and a'valve-controlled connection between the oil reservoir,

an'd the high pressuref side ofthesystem. l

6. In combinationwith 'the elements of the combination specified 'in claim 5, af valvecontrolledconnection between the low pres'- sure side of' the system and the oil reservoir above the level of the oil therein."

In testimony whereof I affix my signature. I THOMAS SHIPLEY.

the compressor valveabove the level-,of 

